A football coach who sent sexually explicit photographs to 14-year-old boys via his phone is to be referred to a programme to help him stop sexual offending.

Stefan Alletson, 23, met the two teenage boys while coaching at a Wellington college last year and began exchanging messages with them by cellphone and on Facebook.

In Wellington District Court, Judge Ian Mill said the messages became increasingly sexual until they exchanged intimate pictures of themselves. Alletson sent one boy an intimate photo of the other boy. Police spoke to Alletson and he said he had done a stupid thing.

He pleaded guilty to two charges of possessing objectionable material and two of supplying objectionable material. He also faced an unrelated charge of breaching a previous community work order.

The judge said a probation report suggested Alletson did not seem to fully appreciate the effect the offending could have on the boys. He said victim impact statements showed the boys were unable to get the offending out of their minds.

''They trusted you, looked up to you ... and you clearly betrayed that trust.''

A specialist report said Alletson needed help and that it would be appropriate for him to do a Wellstop programme to help sex offenders, the judge said. He sentenced Alletson to 18 months' intensive supervision to allow him to do the course, 200 hours' community work, and fined him $500.

Defence lawyer Aaron McIlroy said his client acknowledged intervention was needed and he was willing to do counselling. McIlroy said he had been intending to ask for a discharge without conviction, but that was not now being sought.